Following up on this little discussion with @toscho in chat I went through the first 50 most relevant of 800 questions that contain the word 'iframe' and found there a actually quite some questions that pertain to how to use the <iframe> tag in the WP context. Here's an example I created Before...

I really don't take "down votes" personally but do try to use them to learn how I can improve. I'm relatively new here and want to give back a bit to other new members when I can help answer a question. I was a little surprised to see that my accepted answer was down-voted, here: Create users ...